A role for P-glycoprotein in regulating cell growth and survival

Abstract

Multidrug resistance (MDR) mediated by the adenosine triphosphate (ATP)-dependent drug efflux protein P-glycoprotein (P-gp), is a major obstacle to the successful treatment of cancer. P-gp is expressed in many types of cancers and the clinical success of chemotherapeutic treatment often correlates inversely with the level of P-gp expression. P-gp is a 170-180 kD cell-surface transporter protein and has historically been thought to confer resistance to chemotoxins by actively effluxing them from the cell. While there is little doubt that P-gp plays an important role as an efflux pump in conferring multidrug resistance, new evidence is mounting to suggest that in addition, P-gp may act as a ge..